Micrometer-gage



(N o Model.) Q

J. P. B. WELLS.

MIGROMETER GAGE.

No. 373,705. Patented Nov. 22, 1887.

Edi

UNITED STATES ATENT @rrrcn.

JOHN PERU BEIGE ELLS, OF THOMASTON, CONNECTICUT.

MlCROMETER-GAG E.

SPECIFICATION forming part of Letters Patent No. 373,705, dated November22, 1887.

Application filed January 17. 1E87.

To aZZ whom it 72mg concern.-

Be it known that 1, JOHN PERU BRICE XVELLs, residing at Thomaston, inthe. county of Litchfield and State of Connecticut, have inventedcertain new and useful Improvements in Micrometer-Oalipcrs; and I dodeclare thefollowing to be a full, clear, and exact description of thesame, reference being had to-the accompanying drawings, which form apart of this specification.

My invention relates to an improvement. in micrometercalipers, theobject being to produce an instrument adapted to compensate for wearwithout disturbing its graduations, and to be easily and quicklyadjusted, available for a wide range of precise measurements, andcombining simplicity of construction with durability and generalefficiency in use.

\Vith these ends in view my invention consists in certain details ofconstruction and combinations of parts, as will be hereinafterdescribed, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view, partly in elevationand partly in central longitudinal section,ofone form which myimprovement may assume. Fig. 2 is a view thereof looking toward theouter end of the micrometer-sleeve. Fig. 3 is a similar view from theopposite end of theinstrumcnt. Fig. 4 is a detached view of themeasuring-screw. Fig. 5 is a similar view showing theindependent nut inside and in end elevation. Fig. 6 is asimilar representation of theadjustingnut, and Fi 7 is a view of thetapering bind ing screw.

As herein shown, the barrel A, having the usual graduation and vcrnicr,is made integral with the bow B and provided at its outerend withinterior screw-threads, C, and with a smooth conical or taperingchamber, D, extending inward on a decreasing taper from such threads. Auinteriorly-threaded tapering nut, E, provided in its smaller end with aslit, F, and two deep grooves, F F, is located in the said conicalchamber with its smaller end in the smaller end thereof, and receivesthe measuringscrew G, to which it conforms in threading. Anexteriorlythreaded adjusting-nut, H, having a smooth bore through whichthe said measuring-screw passes and provided in its outer face withslots Serial No. 224.514. (No model.)

I for turning it, is located in the outer end of the barrel, where itengages with the threads 0 thereof and abuts against the outer andlarger end of the tapering nut aforesaid. The outer end of themeasuring-screw G is turned to form a shoulder or sent, J, splitlongi-tudi nally, as at K K K, to make it expansiblc, and tapped, as atL, to receive a tapering bindingscrew, M, by which it is expanded. Themicrometer-sleeve N, fitting over and revolving upon the barrel A, isprovided at its open end with the usual graduation and at its outer oropposite end with a cap made in one piece with it and having an opening,0, receiving the tapering binding'screw M, which holds the said capagainst the shoulder or seat J of the measuringscrew and expands thesplit end of the same into such opening,whereby a friction-couplingbetween the said sleeve and measuring-screw is secured. A hardenedannular steel bushing, P, fits into a. suitable recess, Q. formed in theinner end of the barrel, and forms the forward bearing for the measuringscrew, which has its rear bearing in the tapering nut located in thebarrel, as aforesaid. The outer end of the bow is provided withacylindrical chamber, 1%, open at both ends and receiving the shank S ofan anvil, T, located in line with the measuringscrew and abuttingagainst the inner face of the bow, where it is held by a retainingscrew, U, entering the outer end of the shank, which is thereto drilled,as at V, and engaging with the outer face of the bow, the said shankbeing considerably smaller in diameter than the anvil and fittingclosely into the chamber R aforesaid.

Under myinventiou any wear ofthe calipers or measuring-screw iscompensated for by contracting the threaded nut-bearing. This is done byturning in the adj usting-nut, whereby the tapering nut is forced inwardagainst the tapering walls of its chamber, which close it onto thescrew, the described mode of slitting and grooving the tapering nutpreserving the alignment of its threads and making it very responsiveunder pressure. It is to be noted that this compensation for wear occursentirely in a nut made independent of the barrel, which therefore is notdisturbed in its scaling, and, moreover, that the means of compensationare protected against being started in using the instrument.

By making the measuring-screw and micrometer-sleeve relatively movablethe respect ive graduations of the latter and the barrel may be readilybrought into correct relations when wear in the instrumenthas causedtheir divergence by loosening the tapering bindingscrew and, afterrunning the measuring-screw to the anvil, turning the micrometer-sleeveuntil its zero-line exactly coincides with that of the barrel. Thetapering binding-screw is then turned to couple the sleeve andmeasuring-screw again. Being independent of the sleeve, themeasuring-screw may be readily removed and refaced when worn, or it maybe discarded and replaced.

By providing the anvil with a shank smaller than it in diameter andholding it in place by a retaining-screw entering the outer end of suchshank, which closely fits into an open chamber in the bow of theinstrument, I am enabled to secure the anvil in place without theformation at the end of the bow of the enlargement ordinarily requiredat that point and interfering with the use of the instrument andlimiting the range of the application thereof.

It will thus be seen that no compensation of the tool for wear affectsits graduations and thatthe movability of the sleeve with refer- .enceto the barrel enables a restoration of the instrument, and means foroperating such nut,

scales to right relation if they have been relatively disturbed by wearof the movable parts of the tool, and particularly of themeasuringscrew.

If desired, the independent nut located in the barrel may assume otherforms than that herein shown. Thus it may be made cylindricaland-contracted by a nut located upon it. I would therefore have itunderstood that I do not limit myself to the exact construction andarrangement of parts herein shown and described, but hold myself atliberty to make such slight changes and'alterations as fairly fallwithin the spirit and scope of my invention.

Having fully described my invention, what Iclaim as new, and desire tosecure by Letters Patent, is-- 1.. A micrometer-caliper having a barrel,a micrometer-sleeve, a measuring-screw, an independent contractile nutlocated in the barrel and threaded to receive the screw, and anadjusting-nut, also located in the barrel and arranged to operatethe'contract-ile nut, substantially as set forth.

'2. A micrometer-caliper having a barrel provided with an interiortapering chamber, a movable contractile taper nut having its outer facesmooth throughout its length, located entirely within such chamber, andthreaded to receive the measuring-screw of the substantially as setforth.

3. A micrometer-caliper having a barrel provided with an interiortapering chamber, a micrometersleeve, a measuring-screw, a contractiletaper nut located in such chamber and threaded to receive the screw, andan adjusting-screw threaded into the barrel and engaging with the tapernut for contracting it, substantially as set forth.

4. A micrometer-caliper having an independent nut located in its barreland threaded to receive its measuring-screw, and provided with one ormore slits and one or more deep grooves to permit its contraction,substantially as set forth.

5. In a micrometer-caliper, the combination, with a measuring-screwprovided at its outer end with a shoulder, of a sleeve seated upon suchshoulder and extending forward toward the bow of the instrument, and abindingscrew passing through the outer end of the sleeve and into theouter end of the screw and normally coupling them rigidly together andunscrewed for loosening or uncoupling them for their relative adjustmenttocorrect the instrument, substantially as set forth.

6. A micrometer-caliper having a barrel, a micrometer-sleeve, ameasuring-screw shouldered, split, and drilled at its outer end, themicrometer-sleeve resting against its shoulder,

and a taperingscrew passing through the outer 9 end of the sleeve andentering the drilledend of the screw, which it expands to couple thesame and the sleeve together, substantially as set forth.

7. A micrometer caliper having a barrel, a micrometersleeve, ameasuring-screw, an independent nut located in the barrel and threadedto receive the screw, and a hardenedsteel bushing mounted in the barreland forming the forward bearing of the measuring screw, substantially asset forth.

8. A micrometer-caliper having an anvil provided with a shank smallerthan it in diameter and closely fitting into an open chamber in the bowof the instrument, and a retaining-screw entering the outer end of suchshank and engaging with the outer face of the bow, the inner face ofwhich is engaged by the anvil, substantially as set forth. 7,

9. A micrometer-caliper having a bow, at

barrel, a micrometer sleeve, a measuringscrew, an anvil provided with adrilled shank of smaller diameter located in the bow in line with themeasuring-screw, and a retainingscrew entering the said drilled shank ofthe anvil and engaging with the outer'face of the bow, substantially asset forth.

In testimony whereoflhave signed thisspecification in the presence oftwo subscribing witnesses.

JOHN PERU BEIGE WELLS.

Witnesses:

JOHN FRANCIS .TENKs, J r., FRANK W. ETHERIDGE.

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